The main problem for those vying to be TripAdvisor 2.0 is the battle for online visitors – managing to survive as a new website until a critical mass of reviews has been achieved, and enough social buzz to make them successful. "TripAdvisor's omnipresence is key when it comes to its success," says online marketing specialist Adam Davidson. "Wherever you are planning to stay or eat, you know and expect TripAdvisor, will have it covered – many other sites can't match that." Those that currently do tend to be owned by or part of the big travel firms: "A lot of big holiday companies such as Thomson and Booking.com have their own user-review systems now," says May. "With Booking.com an email arrives in your inbox as you land on the way home saying: 'Hi. What did you think of the hotel?' By asking for the review after the booking is made, they are also verifying it's authentic." Differentiation could be the key to a new site's success, according to Davidson. "While it is difficult to get the ball rolling, once they reach a meaningful breadth of reviews, perhaps in a niche market to start off with, something could take off," he says. "The habit of contributing reviews is infectious after all." Get the full story at the Independent.ie